Drysuits vs Semi Dry Suits

As a keen member of Perth SubAqua club I have spent most of my 23 dives to date in the cold Scottish Lochs on the west coast. I have dived in Ballachulish, Loch Fyne, Skye, Oban, and Ullapool which is one of the top dive sites in the world (sea horses can be seen here.)

For the first year my diving was hampered due to starting off my training using what’s called a Drysuit that was several sizes too big. The drysuit doesn’t let water in, so the diver stays dry(er) however, if the suit is too big it can fill with air pockets which cause the diver to shoot up to the surface – this can be dangerous by causing the ‘bends’ condition where nitrogen forms bubbles in the blood stream.

My diving started to improve when I had the opportunity to purchase one of my club member’s Scubapro Novascotia Semi Dry suit. At the time I didn’t even know what a semi dry suit was, however the first time I tried it at the Farne Islands last September (2015) I saw a dramatic difference in my ability to stay under the water.

Semi Dry suits let water in much like a Wet suit does, however the semi dry keeps that water in via the seals on the neck, wrists and ankles. This allows the body to heat up the water to retain a liquid layer of insulation.

The advantages of the semi dry are that it’s cheaper to buy than a drysuit. The semi dry clings to your body, eliminating air pockets. It’s also simpler to dive with as there’s no chest valve to inflate – you can only inflate your BCD / stab jacket – so less technical bits to worry about.

The disadvantages – WARNING – semi dry suits are not designed for diving in the Scottish Winter months! Due to my passion for diving I have used the Novascotia in temperatures down as low as 7 degrees centigrade. The feeling is quite unpleasant and often I am shivering, so that after 30 minutes, I don’t want to be in the water. I think I am one of the few club members that still dives with a semi dry. I later was given a handy tip from one of the more experienced club members and discovered that wearing a wool jumper underneath helps a little, to retain some warmth in a semi dry.

The other disadvantage of the semi dry is that it’s made of neoprene which tends to tear more easily on rocks. The new Novascotia 7.5mm suit has much more protection on the knees than my older 6.5mm version. However saying that, Scubapro kit is award winning, so it’s a very good standard of dive suit. Semi drys are much more suited to water temperatures of 12 degrees or above, as I discovered in the warmer Farne Islands dive. If you’re not cold you’re going to enjoy the dive more. No matter how hard you try, if you start shivering the dive becomes a chore and that’s a shame.

Here’s an excellent video review by Jeff Goodman on the new N0vascotia 7.5mm Semi Dry Suit

Maintenance: after a dive I can spend up to over an hour and a half rinsing and cleaning my diving kit. I invested in a bottle of McNett suit shampoo which I use to wash over the Novascotia, my Stab Jacket and well, pretty much most of my kit. I realised that I spend the same amount of time cleaning my diving kit as I did cleaning my motorbike. (I decided to get rid of the bike as I much prefer my diving.) It’s worth it though, to keep your kit nice and clean after being in the sea lochs.

It takes approximately 4 to 5 days for my semi dry to dry out, so at least in theory, I could use my suit every Sunday if I wanted to. Last Sunday myself and two colleagues from the club set off from Perth to Furnace quarry near Inveraray on the Scottish west coast. We always dive on the west as the water is usually warmer and calmer, getting some of that gulf stream flowing in.

This was my second dive at Furnace quarry – the first time was in December last year and I remember it was so cold that I was shivering when I still had my clothes and coat on! This dive is a cold and dark one, although there’s enough visibility at 24 metres to see some Wolf fish that look like mini sharks. One of our colleagues had a problem with his chest valve leaking so he was out the water before getting in. It was then that I realised the advantage of the semi dry.

The temperature was COLD! Eight degrees and after 15 minutes I was shivering and wanting to just get to the surface, however, I persevered to the end and felt much better after completing the dive safely with my dive buddy. I often check the water temperature online and I think the sea temperature has now gone up by one degrees since the winter.

I look forward to the day when I will be able to go to Malta to dive in the warm water, just wearing my Scubapro Everflex wet suit. Meantime, I will persevere and look forward to updating you with another blog on my next dive – and more often too!

For more information on semi dry suits available check out Simplyscuba’s website.